Azobisisobutyronitrile → Ethyl 4-[4-chloro-7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]butanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 4-[7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]butanoate (9.7 g, 30.5 mmol) and 2,2′-azobisisobutyronitrile (AIBN; 0.5 g, 3.05 mmol) in chlorobenzene (100 mL) was added N-chlorosuccinimide (NCS; 4.35 g, 32.6 mmol) in portions at 65° C., and the mixture was stirred at 80-90° C. for 2 days. After cooled to room temperature, the reaction mixture was partitioned between ethyl acetate (50 mL) and water (50 mL). The aqueous phase was extracted with ethyl acetate (100 ml×3), washed with brine (100 mL), dried over anhydrous sodium sulfate and purified by silica gel column (petroleum ether/ethyl acetate, 50/1) to afford the title compound (6.8 g, 61%) as yellow oil.

Provenance & Evidence